1. Field of the Invention
For use with developers and activators as a supplement, conditioner, or as the basis of a formula to be used with photographic or radiographic processes and materials, widely used in but not limited to the graphic arts, printing, photography, radiography, publishing, medical, dental, microform, science, journalism, and aerospace industries.
2. Descriptions of the Prior Art
All other prior art makes claims as preservatives to extend either storage life or aging life, not usage life, and is almost always specifically targeting or proportioned for use with either color, or B&W, using different chemicals and compounds than those of this invention, and employing either standard industry methods or different methods not relative to those of this invention.
U.S. Pat. No. 3,928,042 issued Dec. 23, 1975 claims preservative benefits through the use of salts, esters and amides of plicatic acid for the extension of storage life only. Column 2 line 50 states "The preservatives of the invention therefore achieve best results and are accordingly preferably used in photographic negative processing or with photographic stock solutions prior to their dilution for photographic paper processing". Prior to their dilution|
U.S. Pat. No. 3,549,370 issued Dec. 22, 1970 claims quaternary ammonium bisulfites, sulfites or pyrosulfites as developer preservatives. No claims are made purporting the extension of usage life but instead claims the promotion of preservative effects with all kinds of hardeners, alkalines and alkaline buffer systems.
U.S. Pat. No. 3,713,826 issued Jan. 30, 1973 claims sulfite esters as preservatives for B&W developing agents. This patent applies only to B&W developers which does not encompass color, radiographic, graphic arts materials such as lith, rapid access, hybrid chemistries, or the new fourth generation chemistries.
U.S. Pat. No. 3,627,530 issued Dec. 14, 1971 photographic developer solutions of high sulfite content and pH states usefulness in forming multicolor images in color films and in forming colored radiographic images. It also states that developer baths are stable over a long period of time but is specifically related to color photography. Stability is achieved in many ways. Stability does not mean repeatable usage life extensions. More specifically it is touted for use with "rapid access radiographic processes."
U.S. Pat. No. 5,252,439 issued Oct. 11, 1993 promotes a method of replenishing solution with replenisher and is specifically geared towards color developer replenishment. The use of two different replenishment solutions of opposing pH's are used to avoid precipitate.
U.S. Pat. No. 4,923,787 issued May. 8, 1990 photographic element containing scavenger for oxidized developing agent uses hydrazide as the scavenger and is for use in the prevention of fog and stain formation in developed color images.
U.S. Pat. No. 5,196,298 issued Mar. 23, 1993 photographic developing solution containing an ascorbic acid derivative. The developing properties of ascorbic acid have been published since the turn of the century. This invention promotes the lack of sulfite ions.